1. Technical Field
The present invention relates to a shake detection device, a shake detection method, and a shake detection program that detect a shake amount of a camera to be generated when photographing a subject.
2. Related Art
One known technique for detecting the motion of an electronic apparatus and correcting or controlling the functions of the electronic apparatus according to the detected motion involves mounting a detection device for detecting motion, such as a gyroscope or the like, on the electronic apparatus. For example, when the electronic apparatus is an imaging apparatus, such as a digital camera, a shake amount to be generated upon photographing as a motion of the camera is detected using a detection sensor, such as a gyroscope, and a photographing condition upon photographing is corrected based on the detected shake amount, thereby suppressing a vertical or horizontal image shift amount from being generated in a photographed image (see JP-A-5-142613 or JP-A-9-189932).
Further, in detecting the shake amount, at least two detection sensors are usually used to detect the shake amount in order to calculate an accurate shake amount. JP-A-5-142613 discloses a technology that detects a shake amount by disposing two detection sensors at a grip position of a camera. JP-A-9-189932 discloses a technology that detects a shake amount by disposing two detection sensors in the vicinity of a pentaprism.
Recently, an imaging apparatus, such as a camera-equipped cellular phone or the like, has been reduced in size, and a battery to be mounted on the imaging apparatus has also been reduced in size accordingly. For this reason, in order to prevent the lifespan of the battery from being shortened, there is a need for a power saving measure that reduces the current consumption of the imaging apparatus.
As the detection sensor for detecting the shake amount, a gyro sensor that uses a vibrator, such as a piezoelectric vibrator, is usually used. A predetermined angular speed around an axis is detected by detecting a change in vibration state of the vibrator. For this reason, in order to detect the shake amount, the piezoelectric vibrator needs to be driven and to vibrate at all times, and thus a driving current needs to flow in the detection sensor at all times. Accordingly, the detection sensor consumes the electric current, which shortens the lifespan of the battery.
However, in JP-A-5-142613 and JP-A-9-189932, a technology about current consumption upon shake detection is not disclosed. Although the shake amount is detected by the detection sensor and an image shift of a subject can be suppressed from occurring in a photographed image, there is a problem in that the lifespan of the battery is shortened.